@prefix isq: <https://w3id.org/standards/isq/ontologies/core/> .
@prefix smart: <https://example.org/smart-sdu/> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix dcterms: <http://purl.org/dc/terms/> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .

<isq:t7-21>
  a isq:Entry ;
  rdf:type isq:Quantity ;
  rdf:type smart:TermEntry ;
  dcterms:identifier "7-21" ;
  skosxl:prefLabel "photon intensity"@en ;
  skosxl:altLabel "I_\"p\""@en ;
  skosxl:altLabel "(I)"@en ;
  skos:definition "density of photon flux with respect to solid angle in a specified direction, expressed by\n\n[stem%unnumbered]\n++++\nI_\"p\" = (\"d\"Phi_\"p\")/(\"d\"Omega)\n++++\n\nwhere stem:[Phi_\"p\"] is the photon flux (<<t7-20>>) emitted in the given direction, and stem:[Omega] is the solid angle (<<iso80000-3>>) containing that direction\n"@en ;
  smart:hasBindingnessType "bindingness-type:normative" ;
  dcterms:isPartOf <isq:part-7> ;
  isq:hasUnit [
    skos:notation "s^(-1)*sr^(-1)" ;
    skosxl:prefLabel "per second steradian"@en
  ] ;
  skos:note "The distribution of the photon intensities as a function of the direction of emission, e.g. given by the polar angles stem:[(vartheta, varphi)], is used to determine the photon flux (<<t7-20>>) within a certain solid angle (<<iso80000-3>>) stem:[Omega] of a source:\n\n[stem%unnumbered]\n++++\nPhi_\"p\" = &#8748;_Omega I_\"p\" (vartheta,varphi) \"sin\" vartheta \"d\"varphi \"d\"vartheta\n++++\n\nThe corresponding radiometric quantity is \"radiant intensity\" (<<t7-5.1>>). The corresponding photometric quantity is \"luminous intensity\" (<<t7-14>>).\n"@en ;
  iso:urn <urn:iso:std:iso:80000:-7:ed-2:en:item:7-21> .